1. Field of the Invention
This invention relates to telecommunications systems and more particularly to systems for connecting users in a service area to telecommunications service.
2. Description of Related Art
Growing cities and towns or new towns in rural areas require an infrastructure of basic services. One such service is telephone service. To provide the infrastructure for telephone service, telephone service providers deploy copper or fiber-optic cable from a central office (CO) to the customer locations and build any structures associated with deployment of the cable.
Telephone service providers typically deploy the cable by connecting cables having successively lower capacities between the CO and the customer location. Cables with a first capacity, such as for example, DS3 cable, are deployed between a CO and a service area interface. A DS3 cable can carry a DS3 signal, which is a digital telephone signal that transmits at 44.736 Mbs. A DS3 cable is capable of carrying 672 pulse code modulation (PCM) voice channels. At the service area interface, the DS3 cable may be divided into several cables, which can carry 96 voice channels, or DS1 cables, which can carry 24 voice channels. The lower capacity cables branch out from the service area interface to different areas such that each DS1 cable serves a group of customers. DS1 cables extend to a terminal from which drops are made to a network interface at a customer's location.
The DS1 signals can be carried on either optical or copper cables. DS3 signals are carried by optical cables. Signals having higher capacities may be carried by optical, coaxial or by radio or wave-guides.
Prior to the use of optical cable, radio was historically used for inter-office trunking because of its capacity and to take advantage of the central office structure, which provided environmentally controlled conditions. The high density traffic carried over inter-office/trunking justifies the cost of using radio, particularly in mountainous or otherwise harsh environments where installing cable would be more expensive.
The cables are typically buried, or carried in underground conduits, although copper cables may be supported on telephone poles.
The cables terminate at the service area interfaces or at the terminals in structures that are built by the service providers. The structures may be huts, which have facilities for environmental conditioning such as power, fans, heating and air conditioning. The service providers may also build cabinets, which are lower cost structures that are typically used for cross-connections and electronic equipment.
Growth in some areas can be so fast that telephone service providers have difficulty in keeping up with demand for service. First of all, depending on the distance to the nearest terminal or end office, the process of burying the cable, or laying the conduits may be time-consuming. Moreover, the process of acquiring the land, whether by purchase or by lease, prior to installing the cable may result in further and more unpredictable delays.
It would be desirable for service providers to provide an infrastructure for telephone service quickly and efficiently. Additionally, in areas where cable is best suited to provide service, it would be desirable to provide a temporary medium for telephone service that can be deployed in a more timely manner that is re-usable and easily removed when permanent cable installations are available.